"The main message of our study is that we are using chronic medication a lot more than we used to," Donna Halloran, MD, a professor of pediatrics at St. Louis University, tells WebMD. "We know obesity causes other medical complications, like diabetes, high blood pressure, cholesterol problems, and depression."

Chronic Medications for Kids: The Upside

Though there is no known link between obesity and ADHD, pediatricians are increasingly choosing drug therapy for it, too, she says.

"More medication use is not bad," Halloran tells WebMD. "Better diagnosis for all these things is good. High blood pressure needs to be treated. Asthma also, and diabetes and depression."

Robert Geller, MD, a professor of pediatrics at Emory University School of Medicine in Atlanta, tells WebMD it's likely more youngsters are taking drugs for ADHD because "there's been a reduction in the stigma" associated with those conditions.

"Now people are more willing to admit it and get appropriate help," he says.

The study doesn't answer whether asthma severity and incidence are related to increasing obesity among young people, he says, but the problems seem to have some overlap.

Halloran and colleagues studied prescription claims data for more than 3.5 million commercially insured youngsters between 5 and 19, covering the period 2002 to 2005.

During that period, the prevalence rate for diabetes medicines among those youngsters doubled, and asthma medication use jumped 46.5%, the study shows. Drug use to combat ADHD rose 40.4%, and 15% for medications to lower lipids and cholesterol.

"We are seeing more disease, better detection of disease, and more use of medication," she says. "We don't know the risks for long-term medication use, but better diagnosis is a good thing."

Scientists don't know if there's a link between obesity and ADHD or obesity and asthma, she says, and "we don't know whether obesity causes depression or vice versa. But a tie-in would make sense."